“Wall Street is riddled with such counterintuitive sector placements, and this has become more of an issue as companies expand into business lines that are outside of their primary industry,” reports Ryan Vlastelica for MarketWatch.

What may be confusing investors is that they view Amazon and Netflix as Internet stocks along the same lines of Alphabet Inc. (NASDAQ: GOOG) and Facebook Inc. (NASDAQ: FB). All four are found in Internet ETFs, but Alphabet and Facebook are classified as technology stocks and therefore, at the sector level, reside in technology ETFs.

“A number of companies appear in sectors that one might not expect. American Express Co. AXP, +0.93%  is in the financial sector, but credit card rivals Visa Inc. V, +0.00%  and MasterCard Inc. MA, +0.44%  are both classified as technology names,” according to MarketWatch.

Adding to the confusion is that Amazon, in particular, and Netflix have exposure to cloud computing as does Facebook. In fact, Amazon is one of the largest cloud companies in the world and most companies with cloud exposure are classified as technology, not consumer discretionary firms.

“Sector assignments are dictated by the global industry classification standard, which is a joint effort between S&P Dow Jones and MSCI. To classify a company, the GICS team looks at its different revenue streams, which determine what various subindexes the company fits into,” according to MarketWatch.

Tom Lydon’s clients own shares of Facebook.